Engine temps -DX8 Telemetry

[J-S-Q]

I had the first few flights with the DX8 telemetry setup on my 700N (with an OS 91HZ-R engine) and I was surprised how high the engine temperatures were. In flight, the DX8 was recording maximum temperatures in the high 120's although it was much cooler when landing (probably something in the 80's) and the backplate was warm but I could hold my finger on it indefinitely without a problem. I have the sensor wrapped around the cylinder wall, pushed in between the highest fins, just below the cylinder head. Is anyone else using the engine temp sensor and if so, what kind of readings are you getting?

[sacko]

About 25 degrees higher.

Not really sold on it tbh.

[J-S-Q]

About 25 degrees higher.

Not really sold on it tbh.

You mean about 25 degrees higher than me??? i.e. over 150 degrees?

Are you not sold on it being accurate or are you just not sold on it being a useful function?

[millerman]

i have mine in the same place and i have been getting readings around the 95 to 110 mark works just fine as far i im concerned
i also have one on my 700 which has carb smart on set to 100 degs and that engine always stays around the 100 mark give of take +-2/3 degs so im happy with it

[J-S-Q]

i have mine in the same place and i have been getting readings around the 95 to 110 mark works just fine as far i im concerned
i also have one on my 700 which has carb smart on set to 100 degs and that engine always stays around the 100 mark give of take +-2/3 degs so im happy with it

When you say 95-110 are you talking about the screen that shows the maximum recorded temp for the whole flight? I was thinking about getting a Carb Smart actually because I used to have one on my 600N and it worked pretty well.

[Tim Procter]

i have mine in the same place and i have been getting readings around the 95 to 110 mark works just fine as far i im concerned

ditto.

[millerman]

When you say 95-110 are you talking about the screen that shows the maximum recorded temp for the whole flight? I was thinking about getting a Carb Smart actually because I used to have one on my 600N and it worked pretty well.

gotta admit i only check em a few times in flight and rarely look at the max min screen but when tuning and stuff i check it a few times or if the engine does not sound on tune i check it im kind of getting used to the sound and smoke pattern of the engines now rather than relying on temps but it does help

[J-S-Q]

ditto.

Again Tim, are you talking about the actual max recorded temp, or just the general temp level when you happened to look at the screen? Mine were probably something around that level too generally speaking but if I did something like a Tic Toc, they would rise a lot -I know that because I set the alarm to go off at 125c and during the Tic Toc the alarm would sound but 5-ish seconds afterwards, it would cool down and stop sounding.

[Tim Procter]

Again Tim, are you talking about the actual max recorded temp, or just the general temp level when you happened to look at the screen? Mine were probably something around that level too generally speaking but if I did something like a Tic Toc, they would rise a lot -I know that because I set the alarm to go off at 125c and during the Tic Toc the alarm would sound but 5-ish seconds afterwards, it would cool down and stop sounding.

Actual max temp of course.

If my buzzer was sounding in flight due to hard work you can be sure my heli would be landed pronto.

To check my temps it's pretty obvious no one views the telemetry screen in flight so I work it hard and sit it down fast then shoot to the screen to read it before the heli cools down.

It only takes seconds to cool down so IMO get the engine working pretty good pulling hard and leave it there.

If the buzzer sounds due to high temps land the bugger quick.

[J-S-Q]

Well maybe my engine is just not tuned well (I'm certainly not a tuning expert) but it's always been cool enough with the post flight backplate test, good smoke etc. but perhaps has been running lean for brief periods in flight all along -although I've had it nearly a year and when I replaced the back bearing the other week it looked good as new inside. That's the problem with this bloody telemetry -more things to worry about. lol. Anyway, I may well chuck a Carb Smart on there and be done with it.

And yes, agreed it is not very wise to look at the screen during flight. lol

[Nick B]

I'm in agreement with Tim,120+ will show on most tuned engines during stick banging/pitch pumping manouvres as the gov will be in overdrive but will have an average of 90ish at normal levels of the flight.

Must say seeing 125 spooked me into going richer at first but the engine was 60-70 straight after landing so i did what Tim mentioned,took off,tick tocked for 20 seconds hard and land asap,back down to 90 everytime.And thats what i go on now.

[J-S-Q]

I'm in agreement with Tim,120+ will show on most tuned engines during stick banging/pitch pumping manouvres as the gov will be in overdrive but will have an average of 90ish at normal levels of the flight.

Must say seeing 125 spooked me into going richer at first but the engine was 60-70 straight after landing so i did what Tim mentioned,took off,tick tocked for 20 seconds hard and land asap,back down to 90 everytime.And thats what i go on now.

Yes, I was also tempted to richen it up but that went against my instinct as everything apart from the telemetry was telling me that it was running great but if I understood Tim's post correctly, he's saying that if the telemetry was showing peaks of 125c+ he's be landing sharpish to sort out the problem.

[sacko]

Those temps are about right, I normally wouldnt go above 110degrees.

Compared to a couple of IR guns though, the telemetry was about 20degrees above them.

There are too many variables though. Are the guns correct, and is the emissivity calibrated correctly. Is the telemtry correct, mount the sensor on the heatsink fins, or mill a bit away so the thermistor is seated correctly.

Best way to tune though imo, is still to listen to the engine and check the amount of smoke being produced, as I was hoping the telemtry would help me finer tune the YS, but it hasnt.

[Nick B]

But what hes also saying is by the time hes landed the temp has gone back to normal,ie after say doing a hurricane or rainbows .

Its taught me just how good the fans work on these nitros

Next time you fly,just do average pitch pumps up and down,not to fast,nor to slow,this will mimic a normal flight,my definition of a normal flight is say one of Richie Clarkes flights,proper 3D....basically not like kyle dahl or tareq

When you saw your peak temp,what was the most demanding move you did?

[J-S-Q]

When you saw your peak temp,what was the most demanding move you did?

It was during a tic toc which is the most demanding move I'm capable of doing! and I think it did cool down very quickly after that move, so perhaps it is just normal.